1. Technical Field
This disclosure relates to an image forming apparatus, and more specifically to an image forming apparatus including a recording head for ejecting liquid droplets.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having two or more of the foregoing capabilities. As one type of image forming apparatus employing a liquid-ejection recording method, for example, an inkjet recording apparatus is known that uses a recording head (liquid ejection head or liquid-droplet ejection head) for ejecting droplets of ink.
Such an image forming apparatus may have a maintenance device (maintenance-and-recovery device) to maintain and recover the ejection stability of nozzles of the recording head. Maintenance and recovery operation includes, for example, suction recovery operation of sucking and discharging liquid from the nozzles of the recording head by driving a suction device with a nozzle face of the recording head sealed with a suction cap, pressurizing recovery operation of pressurizing and supplying liquid to the recording head to discharge liquid from the nozzles of the recording head, and dummy ejecting operation of ejecting liquid droplets not contributing to image formation (dummy ejection droplets) to a dummy ejection receptacle or the suction cap.
Conventionally, for example, JP-2007-118317-A proposes a maintenance and recovery method to perform any cleaning operation of normal flushing of ejecting ink from nozzles, minute-amount flushing of ejecting a smaller amount of ink from nozzles than normal flushing, and sucking ejection of ejecting ink from nozzles by sucking ink. For the maintenance and recovery method, an elapsed time after the end of cleaning operation is measured with a timer, and when the elapsed time measured with the timer reaches a predetermined time, minute-amount flushing is performed and the timer is reset to reduce the amount of liquid (ink) consumed by repeating normal flushing and/or sucking ejection when the standby state of the apparatus continues for a long time.
However, for the configuration proposed in JP-2007-118317-A, when the apparatus is in standby state with the apparatus powered on, minute-amount flushing is repeatedly performed each time the predetermined time passes. As a result, it is necessary to eject an amount of droplets sufficient to recover nozzle conditions of the recording head by minute-amount flushing, thus resulting in insufficient reduction effect of the amount of liquid consumed by the maintenance and recovery operation.